[OpenSER-Users] Implementing the Ringing Groups

Hello Users Like Asterisk PBX I implemented the Ringing Group like Ring all, Round Robin and Memory Hunt , RingAll and Round Robin Ringing is working fine with the following UserAgent LinkSys 941 and X-lite, GrandStream, And SJphones, with these is working, When comes to Memory Hunt Ring feature only with Sjphone are working fine, but with User Agent not working the problem is Previous User-Agent number is Not ringing. Can any one tell me solution Why these user-Agents are not working ........ Here is my Memory Hunt logic First A rings Second time A and B rings ( in Failure route Ist time ) Third Time A, B and C ( in Failure route 2 nd time ) Fourth time A, B,C and D rings ( in Failure route 3 time ) -- Thanks &Regards Ravi Prakash Sunkara VoIP Development Tech Lead